The present invention relates to hydraulic elevators.
Conventional hydraulic elevators include a hydraulically driven ram to raise an elevator car. Lowering of the car is typically accomplished by permitting fluid to exit the cylinder of the hydraulic ram and using the weight of the car to force the fluid out of the cylinder. The piston may be directly engaged with the car or may be engaged with the car via a rope fixed to the hoistway and engaged with a sheave on a yoke on the piston. The latter arrangement provides the benefit of not requiring a hole under the hoistway to receive the hydraulic cylinder.
One advantage of hydraulic elevators as compared to traction elevators is the lower cost of the installation. Another traditional advantage is that the machineroom for the hydraulic elevator may be located anywhere in the building, rather than above the hoistway as in traditional traction elevators. Even though the machineroom for a hydraulic elevator may be remotely located, it is still necessary to provide such a space in order to provide a closed and protected area for the hydraulic components: the fluid tank, the pump (typically submerged in the tank of fluid), and the valves associated with the pump and tank. In addition, the machineroom includes a controller that includes the various electrical components for the hydraulic elevator system.
The above art notwithstanding, engineers under the direction of Applicant""s Assignee are working to develop improved hydraulic elevator systems that minimize the space requirements for the system.
According to the present invention, a hydraulic elevator system includes a valve block that is remotely located relative to the pump and fluid tank.
As a result of having the valve block separate from the pump and tank, the necessity for a machineroom is eliminated. The pump and tank may be located in the hoistway and the valve block may be located in a cabinet along with various electronic components of the hydraulic elevator system. The cabinet may be conveniently positioned adjacent to a landing so that a mechanic will have access to the valve block and electronic control without having to enter the hoistway.
According to a particular embodiment, the hydraulic elevator system includes a car and a hydraulic cylinder positioned adjacent to the travel path of the car and mounted on a support, and wherein the pump and tank are positioned underneath the support. This arrangement of the cylinder, pump and tank provides a compact configuration that minimizes the space requirements of the hoistway.
According to a further particular embodiment, the cylinder includes a sheave engaged with a rope, wherein the rope is attached to the car by a rope hitch, and wherein the rope hitch is disposed on the car in a position to avoid interference when the car is adjacent to the tank and pump. This particular embodiment provides a configuration that permits the use of a roped hydraulic elevator without a machineroom.
The foregoing and other objects, features and advantages of the present invention become more apparent in light of the following detailed description of the exemplary embodiments thereof, as illustrated in the accompanying drawings.